This article covers the configuration needed to turn on power saving features. Almost all of the features listed here are worth using whether or not the computer is on AC or battery power. Most have negligible performance impact and are just not enabled by default because of commonly broken hardware/drivers. Reducing power usage means reducing heat, which can even lead to higher performance on a modern Intel or AMD CPU, thanks to [[Wikipedia:Intel Turbo Boost|dynamic overclocking]].

This function shows various power settings. Note you either must be root or you must have sudo.

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{{bc|<nowiki>function aa_power_settings ()

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{

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sudo bash -c '

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for i in `find /sys/devices -name "bMaxPower"`;

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do

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for ii in `find $i -type f`;

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do

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bd=`dirname $ii`;

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busnum=`cat $bd/busnum`;

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devnum=`cat $bd/devnum`;

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title=`lsusb -s $busnum:$devnum`;

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echo -e "\n\n+++ $title\n -$bd\n -$ii";

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for ff in `find $bd/power -type f ! -empty 2>/dev/null`;

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do

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v=`cat $ff 2>/dev/null|tr -d "\n"`;

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[[ ${#v} -gt 0 ]] && echo -e " `basename $ff`=$v";

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v=;

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done | sort -g;

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done;

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done;

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echo -e "\n\n\n+++ Kernel Modules\n";

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for m in `command lspci -k|sed -n "/in use:/s,^.*: ,,p"|sort -u`;

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do

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echo "+ $m";

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systool -v -m $m 2> /dev/null | sed -n "/Parameters:/,/^$/p";

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done

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';

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}</nowiki>}}

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== See also ==

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* [[CPU Frequency Scaling]]

Revision as of 22:53, 23 November 2012

This article covers the configuration needed to turn on power saving features. Almost all of the features listed here are worth using whether or not the computer is on AC or battery power. Most have negligible performance impact and are just not enabled by default because of commonly broken hardware/drivers. Reducing power usage means reducing heat, which can even lead to higher performance on a modern Intel or AMD CPU, thanks to dynamic overclocking.